[Question #4179] Risk of false negative from STI test

32 months ago
I had unprotected oral from a masseur (middle-aged Asian lady) when in the US about 2 months ago. It only lasted about 1 minute before I came, but it worried me as I have never had any form of unprotected sex outside of marriage before.

About two weeks later I had soreness in one testicle, and prolonged dribbling of urine after urinating, and went to see my doctor. I have had this issue several times in the past, and a week of Ciprofloxacin usually fixes it. Again he prescribed 7 days of Ciprofloxacin and I took it. After 6 days of taking this, I went and got a first flow urine test (not sure exactly what test) for gonorrhea and chlamydia, which came back negative.

My question is: is there any chance that the fact I was on Ciprofloxacin when taking the STI test affected the results i.e. a false negative?

Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
Your risk of acquiring any STI from receipt of oral sex is quite low.  The fact that you have had similar symptoms in the past also make it unlikely that these recent symptoms are due to an STI but instead, suggests this is a chronic problem such as prostatitis.  When people do acquire STIs from oral sex, the most common STIs are gonorrhea, non-gonococcal urethritis, or quite rarely, chlamydia.  Having been on ciprofloxacin could conceivably make your tests for these STIs negative and could be curative if you had been infected.  What your negative tests do show however is that you are not infected.  You may never know but at this point I would not be concerned that you are infected.  EWH
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32 months ago
Excellent - exactly as I suspected, but still a relief to hear that.
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
Glad to help.  Take. Care.  EWH---